Design and process simulations for coal based direct reduction of iron ores.

Abstract

This report details the design and simulation of a coal based direct iron ore reduction process. The project goal was to design a process that can be used by small scale miners to add value to iron ore. The research on reduction of iron ore has received much attention in the past few decades as a result of the increasing cost and low availability of raw materials. Traditionally, the main sources of iron for making steel were blast furnace hot metal and recycled steel in form of scrap, however, concerns over the limited resources, the high cost of coking coals, and the environmental impacts of coking and sinter plants have driven steelmakers to develop alternative iron making processes that can use non-coking coals to reduce iron ores directly. The designed process uses a rotary hearth as a reductor due to its flexibility in terms of raw material input and operating conditions which gives it ability to use a wide variety of inputs like hematite and magnetite iron ore, iron ore fines and steel mill waste. Emphasis was put on the design of the rotary hearth and the raw materials used. The parts were modelled and assembled in solid-works and the same software was used to test the performance of the process which showed it is capable of operating in temperature ranges of 1250 oC - 1300 oC, producing 1.03 tonnes of iron per hour with the energy consumption of about 28 kWh.